U.S. patent application number 14/653946 was filed with the patent office on 2016-01-28 for turbine housing with dividing vanes in volute.
The applicant listed for this patent is BORGWARNER INC.. Invention is credited to David G. Grabowska, Adam R. Reinke.
Application Number | 20160024999 14/653946 |
Document ID | / |
Family ID | 50979015 |
Filed Date | 2016-01-28 |
United States Patent
Application |
20160024999 |
Kind Code |
A1 |
Grabowska; David G. ; et
al. |
January 28, 2016 |
TURBINE HOUSING WITH DIVIDING VANES IN VOLUTE
Abstract
A turbocharger turbine (10) having a turbine wheel (12) and a
turbine housing (14) with a volute (20). The turbine housing (14)
has dividing vanes (24) in the curved portion (22) of the volute
(20) for use with a turbine (10) as mixed-flow or axial-flow. A
valve (36) controls exhaust gas flow to one or both of an outer
volute portion (26) and an inner volute portion (28) formed on each
side of the dividing vanes (24).
Inventors: |
Grabowska; David G.;
(Asheville, NC) ; Reinke; Adam R.; (Arden,
NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BORGWARNER INC. |
Auburn Hills |
MI |
US |
|
|
Family ID: |
50979015 |
Appl. No.: |
14/653946 |
Filed: |
December 2, 2013 |
PCT Filed: |
December 2, 2013 |
PCT NO: |
PCT/US2013/072587 |
371 Date: |
June 19, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61739985 |
Dec 20, 2012 |
|
|
|
Current U.S.
Class: |
60/602 |
Current CPC
Class: |
Y02T 10/12 20130101;
F02B 37/24 20130101; F01D 17/14 20130101; F01D 9/02 20130101; F01D
17/148 20130101; F02M 26/10 20160201; F01D 5/02 20130101; F01D
17/18 20130101; Y02T 10/144 20130101; F01D 25/24 20130101; F02B
37/22 20130101 |
International
Class: |
F02B 37/24 20060101
F02B037/24; F02M 25/07 20060101 F02M025/07; F01D 25/24 20060101
F01D025/24; F01D 17/14 20060101 F01D017/14; F01D 5/02 20060101
F01D005/02; F01D 9/02 20060101 F01D009/02 |
Claims
1. A turbocharger using exhaust gas recirculation comprising a
turbine (10) having a non-radial turbine wheel (12) and a variable
turbine volute housing (14) with a curved portion (22), the curved
portion (22) incorporating dividing vanes (24) forming an inner
volute portion (28) and an outer volute portion (26); and a valve
(36) that controls exhaust gas flow to one or both of the inner
volute portion (28) and the outer volute portion (26) for use with
the turbine (10) as mixed-flow or axial-flow.
2. The turbocharger of claim 1 wherein the exhaust gas flow
approaches the turbine wheel (12) in an axial direction.
3. The turbocharger of claim 1 wherein the inner volute portion
(28) and the outer volute portion (26) are defined by a hub-side
wall (34) and a shroud wall (32).
4. The turbocharger of claim 3 wherein the dividing vanes (24)
extend from the hub-side wall (34) and have free distal ends (30)
adjacent to the shroud wall (32).
5. The turbocharger of claim 3 wherein the dividing vanes (24)
extend from the shroud wall (32) and have free distal ends (30)
adjacent to the hub-side wall (34).
6. The turbocharger of claim 1 wherein the dividing vanes (24) are
tilted relative to an axis of rotation of the non-radial turbine
wheel (12).
7. A turbocharger using exhaust gas recirculation comprising an
axial-flow turbine (10) having a non-radial turbine wheel (12) and
a variable turbine volute housing (14) with a curved portion (22)
that incorporates dividing vanes (24) extending from a housing wall
(32 or 34) and the dividing vanes (24) each having a distal free
end (30), the dividing vanes (24) forming an inner volute portion
(28) and an outer volute portion (26); and a pivoting valve (36)
that controls exhaust gas flow to one or both of the inner volute
portion (28) and the outer volute portion (26) for use with the
axial-flow turbine (10) wherein the exhaust gas flow approaches the
non-radial turbine wheel (12) in an axial direction.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and all benefits of U.S.
Provisional Application No. 61/739,985, filed on Dec. 20, 2012, and
entitled "Turbine Housing With Dividing Vanes In Volute."
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] This disclosure relates to exhaust gas-driven turbochargers
having a turbine housing with dividing vanes in a curved portion of
a volute. More particularly, this disclosure relates to a variable
turbine volute turbine housing having dividing vanes for use with a
mixed-flow or axial-flow turbine.
[0004] 2. Description of Related Art
[0005] Advantages of turbocharging include increased power output,
lower fuel consumption and reduced pollutant emissions. The
turbocharging of engines is no longer primarily seen from a
high-power performance perspective, but is rather viewed as a means
of reducing fuel consumption and environmental pollution on account
of lower carbon dioxide (CO.sub.2) emissions. Currently, a primary
reason for turbocharging is using exhaust gas energy to reduce fuel
consumption and emissions. In turbocharged engines, combustion air
is pre-compressed before being supplied to the engine. The engine
aspirates the same volume of air-fuel mixture as a naturally
aspirated engine, but due to the higher pressure, thus higher
density, more air and fuel mass is supplied into a combustion
chamber in a controlled manner. Consequently, more fuel can be
burned, so that the engine's power output increases relative to the
speed and swept volume.
[0006] In exhaust gas turbocharging, some of the exhaust gas
energy, which would normally be wasted, is used to drive a turbine.
The turbine includes a turbine wheel that is mounted on a shaft and
is rotatably driven by exhaust gas flow. The turbocharger returns
some of this normally wasted exhaust gas energy back into the
engine, contributing to the engine's efficiency and saving fuel. A
compressor, which is driven by the turbine, draws in filtered
ambient air, compresses it, and then supplies it to the engine. The
compressor includes a compressor impeller that is mounted on the
same shaft so that rotation of the turbine wheel causes rotation of
the compressor impeller.
[0007] Turbochargers typically include a turbine housing connected
to the engine's exhaust manifold, a compressor housing connected to
the engine's intake manifold, and a center bearing housing coupling
the turbine and compressor housings together. The turbine housing
defines a volute that surrounds the turbine wheel and that receives
exhaust gas from the engine. The turbine wheel in the turbine
housing is rotatably driven by an inflow of exhaust gas supplied
from the exhaust manifold.
[0008] There are three primary turbine types used in turbochargers:
axial, radial and mixed-flow. In axial-flow turbines, exhaust gas
flow through the turbine wheel is only in the axial direction. In
radial-flow turbines, exhaust gas inflow is centripetal, i.e. in a
radial direction from the outside in, and exhaust gas outflow is
typically in the axial direction. Initial exhaust gas flow is
perpendicular to the axis of rotation. In mixed-flow turbines, the
exhaust gas flow approaches the turbine wheel in a direction
between the axial direction and the radial direction.
[0009] An axial or a mixed-flow turbine typically has lower flow
resistance than a radial-flow turbine. Often, axial-flow turbines
can be more efficient because the exhaust gas is forced directly
against the entire turbine wheel while for radial-flow turbines the
exhaust gas flows from the side of the turbine wheel and then
around the perimeter of the turbine wheel.
[0010] Various types of turbochargers are known to have differing
capabilities, sizes, characteristics and cost.
[0011] A traditional wastegate turbocharger often operates in a
binary fashion, but is low cost. A wastegate valve assembly in the
turbine housing may include a valve, vent and/or bypass that is
able to selectively route a portion of the exhaust gas around (i.e.
bypassing) the turbine, in order to limit/control turbine work,
thus only utilizing a fraction of the available exhaust energy that
could be extracted from the exhaust gas flow. Thereby, the
wastegate valve assembly regulates exhaust gas flow and ensures
that the turbine wheel is not spun at an undesirable speed.
[0012] A variable turbine geometry (VTG) turbocharger is a more
complex and expensive option, not using a wastegate valve assembly.
The variable turbine geometry allows a turbine flow cross-section
leading to the turbine wheel to be varied in accordance with engine
operating points. This allows the entire exhaust gas energy to be
utilized and the turbine flow cross-section to be set optimally for
each operating point. As a result, the efficiency of the
turbocharger and hence that of the engine can be higher than that
achieved with the bypass control of a wastegate valve assembly.
Variable guide vanes in the turbine have an effect on pressure
build-up behavior and, therefore, on the turbocharger power
output.
[0013] This disclosure focuses on a variable turbine volute turbine
housing for turbochargers having a mixed-flow or axial-flow
turbine.
SUMMARY
[0014] A variable turbine volute (VTV) turbine housing is an
intermediate cost option that enables exhaust gas recirculation
while supporting improved fuel economy. A VTV turbine housing
typically provides more control than a traditional wastegate valve
assembly. The VTV turbine housing increases backpressure more than
the wastegate valve assembly, allowing exhaust gas to be
recirculated as needed.
[0015] Also, an axial or mixed-flow turbine offers lower inertia
than a radial-flow turbine as a key advantage, but it reduces flow
resistance through the turbine thereby making exhaust gas
recirculation difficult. For typical axial or mixed-flow turbines,
the inability to regulate gas flow through the turbine and a
reduced ability to drive exhaust gas recirculation are
addressed.
[0016] Adapting a VTV turbine housing to an axial-flow turbine
raises a special consideration. Parallel walls across the vanes
that are typically used cause space and casting difficulties for an
axial-flow turbine. The vanes can be tilted relative to an axis of
rotation allowing a surface on the opposite wall for both thermal
growth and sealing the vane tips.
[0017] This disclosure provides further for a VTV turbine housing
having dividing vanes in a curved portion of the volute for use
with a mixed-flow or axial-flow turbine. This can deliver
appropriate gas flow to a non-radial turbine wheel. The volute with
dividing vanes in the curved portion in combination with an
axial-flow turbine assists with improved exhaust gas delivery.
[0018] The VTV turbine housing is combined with an axial or
mixed-flow turbine. Due to space requirements of an axial or
mixed-flow turbine, the VTV turbine housing incorporates dividing
vanes into the volute. A prior art flat plate with vanes is not
preferred with axial and mixed-flow turbines since the housing
diameter may be too large. The VTV turbine housing can operate in a
smaller space than a flat plate with vanes.
[0019] The presently disclosed variable turbine volute turbine
housing with dividing vanes in the curved portion improves exhaust
gas recirculation as part of a mixed-flow or axial-flow turbine
while maintaining the benefits of lower inertia.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Advantages of the present disclosure will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0021] FIG. 1 is a cross-sectional view of a turbine housing with a
valve at the inlet and dividing vanes between inner and outer
volute portions;
[0022] FIG. 2 is a cross-sectional view of a turbine housing with a
dividing vane attached on the hub side between inner and outer
volute portions; and
[0023] FIG. 3 is cross-sectional view of a turbine housing with a
dividing vane attached on the shroud side between inner and outer
volute portions.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] A turbocharger is generally known and includes a turbine 10
and a compressor, wherein a compressor impeller is rotatably driven
via a shaft by a turbine wheel 12. The shaft passes through a
bearing housing between a turbine housing 14 and a compressor
housing.
[0025] A variable turbine volute (VTV) turbine housing 14 enables
controlled delivery of exhaust gas flow. In an axial-flow turbine,
gas flow through the turbine wheel 12 is only in an axial
direction. For a mixed-flow turbine, gas flow approaches the
turbine wheel 12 in a direction between the axial direction and a
radial direction. Both such turbine wheels 12 are non-radial.
[0026] The turbine 10 consists of a turbine wheel 12 and a VTV
turbine housing 14. The turbine 10 converts the engine exhaust gas
into mechanical energy to drive the compressor. The exhaust gas
applies pressure and temperature drop between a volute inlet 16 and
an outlet. This pressure is converted by the turbine 10 into energy
to drive the turbine wheel 12.
[0027] The VTV turbine housing 14 includes a volute 20 with a
spiral shape with a curved portion 22 that decreases in size from
the volute inlet 16 toward the turbine wheel 12. The volute 20
surrounds the outer circumference of the turbine wheel 12.
[0028] The VTV turbine housing 14 has dividing vanes 24 in the
curved portion 22 of the volute 20 for use with a mixed-flow or
axial-flow turbine 10 to deliver appropriate gas flow to a
non-radial turbine wheel 12. The volute 20 with dividing vanes 24
in the curved portion 22 in combination with an axial or mixed-flow
turbine 10 assists with improved exhaust gas delivery. The dividing
vanes 24 can define an outer volute portion 26 and an inner volute
portion 28.
[0029] The dividing vanes 24 can be cast into either side of the
volute 20. FIG. 2 shows the dividing vanes 24 extending from the
hub-side wall 34. A distal free end 30 of the dividing vane 24 is
adjacent a shroud wall 32 and an example mixed-flow turbine wheel
112. FIG. 3 shows dividing vanes 24 extending from the shroud wall
32 and the distal free end 30 adjacent to the hub-side wall 34 with
an example axial-flow turbine wheel 212. In the second case, a heat
shield could be designed to be the sealing surface, including a
multi-piece heat shield that could flex when the dividing vanes 24
press on the heat shield with expansion due to temperature
increases. It is understood that the non-radial turbine wheel 12
could be either the axial-flow turbine wheel 112 or the mixed-flow
turbine wheel 212 in combination with the dividing vanes 24 on
either wall 32 or 34.
[0030] The dividing vanes 24 can be tilted relative to the axis of
rotation allowing a surface on the opposite wall for both thermal
growth and sealing the vane tips.
[0031] A valve 36 can be incorporated into the volute inlet 16 to
control exhaust gas flow, primarily with respect to the outer
volute portion 26 as seen in FIG. 1. The valve 36 is preferably
hinged to pivot on the turbine housing 14 to direct gas flow to
only the inner volute portion 28 when closed or to both the inner
volute portion 28 and outer volute portion 26 when open. The valve
36 can also be incorporated as part of the first vane of the
dividing vanes 24 at the volute inlet 16. The flow of exhaust gas
to just the inner volute portion 28 or to both the outer and inner
volute portions 26 and 28 affects the speed of rotation of the
turbine wheel 12.
[0032] The presently disclosed VTV turbine housing 14 with dividing
vanes 24 in the curved portion 22 controls exhaust gas flow and
improves exhaust gas recirculation as part of a mixed-flow or
axial-flow turbine 10 while maintaining the benefits of lower
inertia. Also, the VTV turbine housing 14 with dividing vanes 24 in
the curved portion 22 of the volute 20 accommodates a smaller
overall turbine 10.
[0033] The invention has been described in an illustrative manner,
and it is to be understood that the terminology used is intended to
be in the nature of words of description rather than limitation.
Many modifications and variations of the present invention are
possible in light of the above teachings. It is, therefore, to be
understood that within the scope of the appended claims, the
invention may be practiced other than as specifically enumerated
within the description.
* * * * *